Nucleophilic substitution in the gas phase. The reactions of alkoxide-alkanol negative ions with boron, carbon, silicon, and titanium alkoxides. An ion cyclotron resonance and ab initio study

1987 ◽  
Vol 109 (19) ◽  
pp. 5823-5828 ◽  
Author(s):  
Hans Van der Wel ◽  
Nico M. M. Nibbering ◽  
John C. Sheldon ◽  
Roger N. Hayes ◽  
John H. Bowie
Keyword(s):  
Ab Initio ◽  
Nucleophilic Substitution ◽  
Gas Phase ◽  
Cyclotron Resonance ◽  
Negative Ions ◽  
Ion Cyclotron Resonance ◽  
Ab Initio Study ◽  
Titanium Alkoxides ◽  
Ion Cyclotron ◽  
Boron Carbon

Electron impact studies. CXVIII. An ion cyclotron resonance study of the reactivity of negative ions derived from ethenetetracarbonitrile. Anionic polymerization in the gas phase

1977 ◽  
Vol 30 (10) ◽  
pp. 2161 ◽  
Author(s):  
JH Bowie
Keyword(s):  
Gas Phase ◽  
Electron Impact ◽  
Anionic Polymerization ◽  
Cyclotron Resonance ◽  
Negative Ions ◽  
Ion Cyclotron Resonance ◽  
Impact Studies ◽  
Stable Adduct ◽  
Ion Cyclotron

.The [M·–l CN·I- species from ethenetetracarbonitrile (tetracyanoethylene) reacts with neutral ethene- tetracarbonitrile to give the stable adduct C11N7-. The decomposing form of this adduct eliminates C2N2 to produce C,9N5- which may react with ethenetetracarbonitrile to yield C15N,9-. Analogous anionic polymerization reactions yield a number of detectable peaks in the i.c.r. spectrum of tetra- cyanoethylene, with the structures of the ions possibly corresponding to a. Diagram Polymerization of this type can also be initiated by other nucleophiles including Cl-, Br-, I- and CF3CO2-.

The reactions of [F----HOMe] and [MeCO2----HF] negative ions with acetaldehyde and acetone. An Ion Cyclotron Resonance and ab initio Study

1983 ◽  
Vol 36 (2) ◽  
pp. 289 ◽  
Author(s):  
JC Sheldon ◽  
JH Bowie
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Cyclotron Resonance ◽  
Methyl Formate ◽  
Negative Ions ◽  
Model System ◽  
Ion Cyclotron Resonance ◽  
Ab Initio Study ◽  
Mechanistic Pathway ◽  
System F

The ion [F-- - -HOMe] may be produced by the reaction of CF3O- with methyl formate, a reaction of a type widely used for the production of 'solvated' negative ions. The possible reaction mechanism for the model system F-/HCO2H has been explored by ab initio calculations. The reactions of acetaldehyde and acetone with [F-- - -HOMe] yield stable [M + F-] ions which are thought to correspond to 'solvated' enolate negative ions. Their formation in terms of a mechanistic pathway, recently proposed to account for the formation of [M + RO-] ions from [RO-- - -HOR]/ > CH-CO- systems, is supported by ab initio calculations.

The reactions of alkoxide-alkanol negative ions with carbonyl compounds. An ion cyclotron resonance and ab initio study

1982 ◽  
Vol 35 (12) ◽  
pp. 2471 ◽  
Author(s):  
G Klass ◽  
JC Sheldon ◽  
JH Bowie
Keyword(s):  
Ab Initio ◽  
Carbonyl Compounds ◽  
Cyclotron Resonance ◽  
Negative Ions ◽  
Negative Ion ◽  
Reaction Pathways ◽  
Ion Cyclotron Resonance ◽  
Ab Initio Study ◽  
Reaction Sequence ◽  
Stable Product

Simple alkyl aldehydes, ketones and esters containing the unit >: CH-CO-react with alkoxide-alkanol negative ions [RO----HOR] to form stable [M+RO-] negative ions (neutral denoted by M). The initial intermediate in the reaction sequence is produced by the formation of a hydrogen bond between the negatively charged oxygen of [RO----HOR] and the hydrogen of the > >CH-CO- unit. This intermediate decomposes to the stable product ion by two reaction sequences: (i) by direct elimination of ROH, and (ii) by rearrangement to a decomposing 'doubly-solvated' negative ion in which the central hydrogen of [RO----HOR] and the hydrogen of the >CH-CO unit become identical. As both reaction pathways are complex, all intermediates and certain transition states have been properly defined by using ab initio calculations at the 4-31G level.

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